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UNITED STATES NATIONAL MUSEUM BULLETIN 224 



Thorax: The thorax is rather short and high espe- 

 cially on the metanotum. Whole mesonotum arched, 

 poUinose, with a diiferentiated band of long, stout, ac- 

 rostical setae; there are slightly longer dorsocentral 

 bristles over the middle which become longer behind but 

 are still slender. The lateral bristles are, however, stout 

 as well as long and finely attenuate. There are 2 noto- 

 pleural, 2 supraalar, both rather far to the rear, 1 on 

 the postalar callosity and none on the scutellum. The 

 thick, convex, poUinose scutellum bears scattered, coarse 

 hairs on the disc and some on the margin, and there is 

 no impressed rim. Metanotal callosity poUinose only 

 and marginate posteriorly. Pleuron poUinose with 

 niunerous, long, coarse or bristly haire on the upper 

 and posterior mesopleuron and with coarse, long hairs 

 on the pteropleuron, upper sternoiDleuron and hypo- 

 pleuron. Metapleuron without true bristles but with 

 nimierous, long, bristly hairs in a vertical band. An- 

 terior basalare with 2 or 3 weak bristles or bristly hairs. 

 Propleuron with the usual pile, pronotmii with at most 



1 or 2 weak bristles but with considerable pile. Post- 

 metacoxal area membranous; prosternum fully dissoci- 

 ated. 



Legs: All the femora are distinctly stout, the first 

 four are a little thickened towards the base. The hind 

 pair is a little thickened from the base to the apical 

 fourth where it is again a little narrowed. All bear 

 dense, fine, appressed setae except that the ventral or 

 posterior surfaces are lai'gely bare. Hind femur with 



2 lateral bristles, 1 dorsolateral at the subapex, a similar 

 one dorsomedially, and 2 smaller medial bristles at 

 the apex ; also there are a group of 4 or 5 long, slender 

 bristles ventrally on the basal half, 2 ventrolateral 

 bristles situated at the distal swelling, and at the oviter 

 fourth ventromedially a patch of 10 or 12 short, stout, 

 spikelike microtuberculate bristles attached in 2 rows. 

 Along the basal half medially is a fringe of rather long, 

 bristly hairs which extends to the end of the medial 

 patch of bristles. Hind tibia slender at base, thickened 

 towards the apex. This tibia has a stout, dorsolateral 

 bristle at the base and 1 beyond the middle, another 

 ventrally at the apical fifth ; medial surface with ranked 

 setae on more than the apical half. Hind basitarsus 

 stout or a little swollen, longer than the next three seg- 

 ments. Middle femur with 3 conspicuous, long, basally 

 stout, attenuate, anterior bristles along the middle, 

 evenly spaced and also with 4 similar anteroventral 

 bristles; apex posteriorly with 1 bristle. Middle tibia 

 with 2 weak, posterodorsal bristles beyond the middle 

 and with 4 long, posterior bristles, also 2 still longer 

 posteroventral bristles and along the middle 3 conspicu- 

 ously long, stout ventral bristles. 



Anterior femur with a dorsal fringe of 10 long, fine, 

 bristly hairs and a similar ventral fringe. Anterior tib- 

 ia with a conspicuous, stout, anterodorsal bristle at 

 the base but posteriorly only with a fringe of nmnerous, 

 long, erect, bristly hairs mixed in with which are 3 



elements, which might be described as weak bristles. 

 Claws slender, bent at apex and sharp ; pulvillus long, 

 large; the empodium bladelike. 



Wings: The wings are hyaline, without villi. The 

 marginal cell is closed with a moderately long stalk. 

 The anterior branch of the third vein ends above the 

 apex, the posterior branch an equal distance behind. 

 The base of the second submarginal cell is actually 

 widened anteriorly but the posterior branch of the vein 

 is deflected some posteriorly. Fourth posterior cell and 

 anal cell closed and stalked. Posterior crossvein absent, 

 the veins fused a short distance. Alula large and wide 

 basally ; ambient vein complete. 



Abdomen: The abdomen is comparatively slender, 

 cylindroid and tapered. Sides of first segment with 3 

 stout, pale bristles and numerous, long hairs. Middle 

 of first segment with a fissure or cleft. Surface of 

 abdomen with scattered, fine, appressed setae and abun- 

 dant, long pile laterally on the second segment and 

 shorter pile on the third segment but with a conspicu- 

 ous, dense, characteristic band or patch of pile laterally 

 on the sides of the sixth and seventh segments. The 

 first, second and sixth stemites also bear abundant, 

 long, fine pile. Posterolateral corners of second and 

 third segments each with 2 or 3 moderately stout bris- 

 tles. Males with 8 tergites, the seventh is only one- 

 fourth as long as the sixth across the middle but longer 

 laterally and both of these segments have long, medial, 

 posterior, membranous margins. Eighth tergite in the 

 middle is half as long as the reduced seventh, but a 

 little longer laterally and without pollen. The male 

 terminalia comparatively short but moderately large. 

 The superior forceps broad basally and widely sepa- 

 rated at the base, narrowed along the middle and again 

 widened distally. The gonopod is comparatively long, 

 curving upward to meet the end of the forceps. It and 

 the hypandrium are laterally wedged in between the 

 forceps and the remarkable eighth sternite, which is not 

 only long and wide but has a long, wide, medial, scoop- 

 like, apical process, thick and densely beset with bristles 

 apically. The proctiger is long, rather densely pilose 

 and oblique. 



Distribution: Neotropical: Catostola carrerai Hull 

 (1958) ; may a Carrera and d'Andretta (1953) . 



The species Gtenodontina may a Carrera and d'An- 

 dretta and Catostola carrerai, new species are, I believe, 

 distinct and as they seem to me to be quite different 

 from the genus Ctenodontina Enderlein, as that author 

 illustrated it, I have concluded to make a new genus for 

 them. I have seen at least one and possibly two other 

 midoscribed and larger species from western South 

 America which also belong here. There may be a num- 

 ber of undescribed forms. The curious, oval, depressed, 

 lateral expansion of the female, illustrated by Carrera 

 and d'Andretta (1953) is characteristic; notice also an 

 anterior, rimlike expansion of the posterior coxa. 



